Producing accurate color with a printer or display can be difficult. In particular, it may be difficult to calibrate printers that combine inks of different colors to produce various other colors. If too much or too little ink of one color is added to the combination, the hue of the desired color may not be accurate. Therefore, anything that alters the delivery of any particular ink, such as temperature, humidity, ink drop size, or variance in ink composition, may cause the resulting color to be inaccurate.
One solution is to implement an automatic calibration procedure in which printed output is detected by a color sensor and analyzed for color accuracy. This method may not be appropriate in some circumstances because the resulting calibration may not produce the desired results. In particular, the preferences of an individual may not be accounted for by automatic calibration procedures.
Another solution is to implement a manual calibration procedure in which adjustments to a printer are made based on an observer's opinion of the overall hue of a printer's color output. An observer may notice that color output from a printer is inaccurate, and consequently reconfigure the printer to correct the color inaccuracy. However, using this method it may be difficult for an observer to accurately make determinations about the direction and magnitude of the hue shift.